Apparatus for drying printing colors



Dec. 14, 1965 w. RAlNER 3,2

APPARATUS FOR DRYING PRINTING COLbRS Filed Oct. 8, 1962 2 Sheets-Sheet 1r xxxyxxxxx x x xxxxxxyxxxxxxvx XXXXXAXXXXX HUM F. :t E.

' INVENTOR Mam-6 Emma A 77'OPIYEYS United States Patent Ofifice3,223,030 Patented Dec. 14, 1965 3,223,030 APPARATUS FOR DRYING PRINTINGCOLORS Walter Rainer, Dornhirn, Austria, assignor to Heberlein PatentCorporation, New York, N.Y., a corporation of New York Filed Oct. 8,1962, Ser. No. 228,881 1 Claims priority, application Austria, Oct. 27,1961,

A 8,111/61 4 Claims. (Cl. 101-115) This invention relates to screenprinting machines and tables and more particularly to apparatus fordrying printing colors.

. Two primary methods are employed for screen printing colors upon a webof fabric or sheet material. In one method elongated stationary tablesare utilized upon which the material to be printed is positioned. One ormore screens are movably mounted over the table so that they print inpattern repeats upon the web of fabric. When multi-colored patterns arebeing produced, the process is repeated with a corresponding number ofscreens so that one screen is employed for each color to be printed.

Another type of screen printing machine, which is employed frequently,utilizes the principle, whereby, the web of fabric or sheet material isadvanced in steps over a printing base member or table while the screensremain stationary thereover. A series of pattern repeats are printedupon the web and each step of advancement of the web over the printingbase member corresponds to a single complete pattern.

. Persons skilled in the art will readily realize the importance and thenecessity of drying the colors after they have been printed upon the webof material. If the color of one repeat is not completely dry before thenext adjacent repeat is printed upon the web, then the colors tend tobleed or contaminate each other in an undesirable manner. Further, whena multi-colored pattern is being produced the color from the firstprinting must be dry before the second color is printed thereover, orelse difficulty will be experienced due to the inter action of the twocolors. This is particularly important because, if the first color isnot set or dryed, the printed pattern will tend to lose its sharpness ofoutline or contour when the second or overprint is made. It is to benoted that the solvents in the second color tend to cause the firstcolor to run when the first color has not been allowed suflicient timeto dry. As a further problem the wet color that remains upon the web mayadhere to the screen and be improperly imprinted at another, undesirablelocation upon the fabric.

Heretofore, in order to overcome the aforementioned problems, space wasprovided between the individual pattern printings. This space wouldcorrespond to one or two pattern repeats which would be added at a latertime after the wet color had been allowed to dry. This, of course,required a considerable amount of waiting time and prompted thenecessity of providing large, elongated printing tables or base members.From an economical and commercial viewpoint, faster drying methodsbecame very desirable, instead of relying upon the temperature andhumidity prevailing in the printing room.

Heretofore, it has been proposed to inject heated air by means ofcirculation, either into the chamber or directly onto the web ofmaterial. Another method which has been proposed consisted of providinga drying cart which followed along the edge of the printing tables.However, such a cart may only be used Where the rails for printing cartsare installed. Among other disadvantages these solutions were notpractical from economical considerations.

Further, apparatus for drying printing colors have been known to utilizeinfra-red radiators which were mounted above the printing table. Thedisadvantage with this system is that the workers are constantly exposedto heat radiation. Further, certain colors tend to gel when thusirradiated and their quality is thereby impaired. Radiators which heatthe printing tables have been employed, but they create uneven dryingpatterns whereby various locations of the web of fabric dry with varyingrates of speed.

In general prior art devices have not been particularly effective. Theytend to be uneconomical and inefiicient. Further, such installationsgenerally cause excessively high room temperatures which has adetrimental effect on the performance of the operating personnel.

In order to overcome the foregoing salient problems, I have invented anovel apparatus for drying printing colors which comprises a heating matinterposed between the web of material and the base member. The heatingmat is a laminar structure which is both flexible and resilient so thatthe usual printing felt may be dispensed with, if desired. One of thelayers comprises a heating element, preferably of theelectrical-resistance type. A protective abrasion-resistant layer isdisposed adjacent the web of fabric in order to increase the longevityof the heating element and to aid in dispensing the heat in a uniformand even manner. A heat insulating layer is provided underlying theheat-ing element in order to reduce extraneous heat losses. Further, analuminium foil may be positioned underlying the heat insulating layerfor reducing heat radiation losses.

There has thus been outlined rather broadly the more important featuresof the invention in order that the detailed description thereof thatfollows may be better understood, and in order that the presentcontribution to the art may be better appreciated. There are, of course,additional features of the invention that will be described hereinafterand which will form the subject of the claims appended hereto. Thoseskilled in the art will appreciate that the conception upon which thisdisclosure is based may readily be utilized as a basis for the designingof other structures for carrying out the several purposes of theinvention. It is important, therefore, that the claims be regarded asincluding such equivalent constructions as do not depart from the spiritand scope of the invention.

Specific embodiments of the invention have been chosen for purposes ofillustration and description, and are shown in the accompanyingdrawings, forming a part of the specification, wherein:

FIG. 1 is a side elevation showing an apparatus for drying printingcolors constructed in accordance with my inventive concept;

FIG. 2 is a perspective view showing a printing table having a blanket,heating mat, and printing felt thereon;

FIG. 3 is a vertical sectional view showing the printing table andheating mat thereon;

FIG. 4 is an enlarged vertical sectional view showing the details of theheating mat constructed in accordance with one embodiment of myinvention;

FIG. 5 is an enlarged vertical section showing another embodiment of theheating mat;

FIG. 6 is a plan view showing one embodiment of a heating element;

FIG. 7 is a plan view showing another embodiment of a heating element;

FIG. 8 is an enlarged sectional view taken along line 88 of FIG. 7.

Referring now to the drawings in more detail and particularly to FIG. 1,there is shown an apparatus for drying printing colors in which a web 10of fabric or sheet material is fed into the machine from a convenientoutside source (not shown). The completed or finished web of fabric isdischarged from the opposite end of the apparatus after the printing anddrying processes have been completed.

A plurality of printing base members 12, 14, 16 and 18 are mounted inspaced relationship one to the other. Directly overlying the printingbases and firmly adhered thereto are a corresponding plurality of plates20, 22, 24 and 26, respectively. Disposed above the plates is a heatingmat 28. Generally, one heating mat is of sufiic ient length to overlayor cover a plurality of plates, as shown. Interposed between the heatingmat 28 and the web of fabric 10 is a movable endless belt or blanket 30.The belt is adapted to pass over rolls 32 and 34 which are positioned infixed space relationship one to the other. Rolls 32 and 34 are suitablymounted upon shafts 36 and 38, respectively, for rotation, and one ofthe shafts is driven by outside motive means (not shown). Positionedabove each printing base 12, 14, 16 and 18 are a plurality of stationaryscreens 40, 42, 44 and 46', respectively. Each stationary screen issupplied with color which is to be printed upon the web of fabric as itpasses thereunder. The belt 30 is adapted to carry the web of fabric 10between the screens and their respective printing bases. Usually, theweb 1 is advanced in steps corresponding to the linear length of eachcomplete pattern, and as the web passes beneath each screen it isimprinted with a portion of the pattern. Several different arrangementsmay be employed with the various screens, for example, if a simpleone-color pattern is desired the screen 40 may print the first completepattern, screen 42 prints the third complete pattern spaced apart fromthe first pattern, screen 44 prints the fifth pattern spaced apart fromthe third pattern and screen 46 prints the second pattern between thefirst and third pattern, and so forth. Thus, suflicient time is allowedto elapse between the printing of two adjacent patterns for the colorsto dry. As another example, screen 40 may print one color while screens42, 44 and 46 print additional colors upon the same pattern and, thus,produce a multi-colored design.

Referring now in particular to FIG. 2, the web of material 10 to beprinted overlays the blanket or belt 30. It is to be noted that thebelting material and caliper thereof are such that heat may betransferred therethrough. Rubber or the like material may be employed.The heating mat 28 is disposed adjacent the belt in an underlyingposition, the details of which will be more fully described hereinafter.Interposed between plate 20 and the heating mat 28 is a printing feltlayer 48. This layer is intended to absorb the shock forces when thescreens print upon the web of fabric. Under some circumstances,especially when the heating mat is sufficiently resilient, the feltlayer may be dispensed with. A printing table or firm printing base 12is employed to support the plate 20 as shown.

FIG. 3 is a vertical sectional view showing the printing table 12 andthe heating mat 28 disposed thereon. Electrical terminal connection 50is provided for energizing the electrical heating mat 28 from standardcommercially available power sources. FIGS. 4 and illustrate the heatingmat itself which comprises a plurality of layers. The heating element 52is interposed between an abrasion resistant layer 54 and a heatinsulating layer 56. The abrasion resistant layer 54 may .comprise athin plastic film which is applied by means of spraying. The choice ofthe type of plastic depends upon the required temperature stability dueto the fact that it is in contact with the heating element 52 which hasa temperature range in the order of 390 to 575 degrees Fahrenheit. Ifdesired, finely divided metallic particles may be admixed with theplastic for temperature stability purposes as well as improving the heatconduction. Since the upper surface of this layer is in contact with themoving belt it is desirable that the surface be smooth and abrasionresistant. Preferably, the thickness of this layer is in the order of.019 to .024 inch. The heat insulating layer 56 may be manufactured froma glass fiber netting. The twill binding found in such material providesgood pliability and the fiber glass material has a low heat conductionrate. This layer, also, acts as a heat reservoir and improves theuniform dispersion of the heat from the heating element to the web offabric. Further, glass fiber provides adequate mechanical strength.Preferably, the thickness of this layer is .007 to .008 inch. In orderto prevent heat radiation downwardly, a reflecting layer 58 may beprovided underlying the heat insulating layer- A um num f i v n a th kess n he rder of .004 inch may be employed for this purpose.

According to the concept of my invention, the heating element 52 mayassume various forms as illustrated in FIGS. 6, 7 and 8. FIG. 6 showsthree longitudinally extending adjacent metallic strips 60, 62 and 64,each of which is connected to one phase of a three phase alternatingcurrent supply as shown at 66, 68 and 70 respectively. The opposite endsof the strips are each connected to a common ground connection 72, thus,forming an electrical resistance heater. FIG. 7 illustrates a heatingelement comprising a plurality of metal and fiber Wires or threadsmaking a netting or screenlike pattern. Various weaving patterns may beemployed, for example, the warp threads may consist of groups ofmetallic conducting Wires and the weft threads may consist ofnonmetallic or inorganic fibrous material. The fibrous materials act aselectrical insulation as Well as providing a heat insulating layer.Strips or groupings of Wires 74, 76 and 78 are each made up from aplurality of individual wires 80. Each grouping of wires are connectedto one phase of a three phase electrical supply source 82, 84 and 86,respectively. The opposite ends of the groups of wires areinterconnected to a common ground connection 88. Within the concept ofmy invention, there are many methods by which the conducting andnon-conducting threads or wires may be interrelated. FIG. 8 illustratesa Weave showing conductive wires 80 intermingled with non-conductivethreads 90. With this type of heating apparatus, it is possible undercertain circumstances to omit the separate heat insulating layer 56mentioned heretofore. Preferably, the thickness of the heating elementis in the order of .007 to .008 inch.

In view of the foregoing, it is seen that the heating mat is resistantto pressure, resilient and flexible, thus undesirable bulges or foldsare not encountered therein.

Although particular embodiments of the invention are herein disclosedfor purposes of explanation, further modifications thereof,'after studyof this specification, will be apparent to those skilled in the art towhich the invention pertains. Reference should accordingly be had to theappended claims in determining the scope of the invention.

What is claimed and desired to be secured by Letters Patent is:

1. A screen printing device comprising a base means extending along agiven path and adapted to support an elongated web of material to beprinted, a plurality of screen printing members spaced .along said pathand each of which is positioned to print upon the web of materialpassing over said base means, motive means arranged to move the web ofmaterial along said base means and said screen members, and a flexibleresilient mat coextensive with said base means and lying on the surfaceof said base means for supporting said web, the resiliency of said matbeing such that it absorbs the shock forces which occur when the screenmember prints upon the web, said flexible resilient mat including, as alamination thereof, an electrical resistance heater of fabric-likematerial.

2. A screen printing device comprising a base means extending along agiven path and adapted to support an elongated Web of material to beprinted, a plurality of screen printing members spaced along said pathand each of which is'positioned to print upon the web of materialpassing over said base means, motive means arranged to move the web ofmaterial along said base means and said screen members, and a flexibleresilient mat coextensive with said base means and lying on the surfaceof said base means for supporting said web, the resiliency of said matbeing such that it absorbs the shock forces which occur when the screenmember prints upon the web, said flexible resilient mat including, as alamination thereof, an electrical resistance heater of fabriclikematerial and further including, as another lamination thereof, a heatinsulating layer between said electrical resistance heater and said basemeans.

3. A screen printing device comprising a base means extending along agiven path and adapted to support an elongated web of material to beprinted, a plurality of screen printing members spaced along said pathand each of which is positioned to print upon the web of materialpassing over said base means, motive means arranged to move the web ofmaterial along said base means and said screen members, and a flexibleresilient mat coextensive with said base means and lying on the surfaceof said base means for supporting said web, the resiliency of said matbeing such that it absorbs the shock forces which occur when the screenmember prints upon the web, said flexible resilient mat including, as alamination thereof, an electrical resistance heater of fabric-likematerial and further including as another lamination thereof, a. heatreflecting layer interposed between said electrical resistance heaterand said base means.

4. A screen printing device comprising a base means extending along agiven path and adapted to support an elongated web of material to beprinted, a plurality of screen printing members spaced along said pathand each of which is positioned to print upon the web of materialpassing over said base means, motive means arranged to move the web ofmaterial along said base means and said screen members, and a flexibleresilient mat coextensive with said base means and lying on the surfaceof said base means for supporting said web, the resiliency of said matbeing such that it absorbs the shock forces which occur when the screenmember prints upon the Web, said flexible resilient mat including, as alamination thereof, an electrical resistance heater of fabriclikematerial having conductive wires interposed between non-conductivethreads and further including as another lamination thereof, a flexibleresilient layer between said electrical resistance heater and said basemeans.

References Cited by the Examiner UNITED STATES PATENTS 2,412,843 12/1946Spraragen 219S 2,623,464- 12/1952 Rodenburg et a1. 10'1126 X 2,634,3614/ 1953 Reynolds 2l9345 2,758,540 8/1956 Laupman 101-126 EUGENE R.CAPOZIO, Primary Examiner.

ROBERT E. PULFREY, Examiner.

1. A SCREEN PRINTING DEVICE COMPRISING A BASE MEANS EXTENDING ALONG AGIVEN PATH AND ADAPTED TO SUPPORT AN ELONGATED WEB OF MATERIAL TO BEPRINTED, A PLURALITY OF SCREEN PRINTING MEMBERS SPACED ALONG SAID PATHAND EACH OF WHICH IS POSITIONED TO PRINT UPON THE WEB OF MATERIALPASSING OVER SAID BASE MEANS, MOTIVE MEANS ARRANGED TO MOVE THE WEB OFMATERIAL ALONG SAID BASE MEANS AND SAID SCREEN MEMBERS, AND A FLEXIBLERESILIENT MAT COEXTENSIVE WITH SAID BASE MEANS AND LYING ON THE SURFACEOF SAID BASE MEANS FOR SUPPORTING SAID WEB, THE RESILIENCY OF SAID MATBEING SUCH THAT ITS ABSORBS THE SHOCK FORCES WHICH OCCURS WHEN THESCREEN MEMBER PRINTS UPON THE WEB, SAID FLEXIBLE RESILIENT MATINCLUDING, AS A LAMINATION THEREOF, AN ELECTRICAL RESISTANCE HEATER OFFABRIC-LIKE MATERIAL.